Click the Bookmarks button
and select Show All Bookmarks to open the Library window.

In the Library window, click Import and Backup and choose Import Data from Another Browser…. The Import Wizard will open.

Note: If Import Data from Another Browser… is disabled (greyed out), you may be in Private Browsing mode. Turn off that feature and try again.

Click the Bookmarks button
and select Show All Bookmarks to open the Library window.

In the Library window, click Import and Backup and choose Import Data from Another Browser….

Note: If Import Data from Another Browser… is disabled (greyed out), you may be in Private Browsing mode. Turn off that feature and try again.

Select the browser that contains the bookmarks or other data that you want to use in Firefox and then continue to the next screens to make your selections and complete the import.

If the Import Wizard does not list your other browser, you can still import bookmarks from another browser but you will need to first export and save those bookmarks as an HTML file. Visit the support site for your other browser if you need help with that.